Water is the only effective and economical medium available for application of various agrochemicals in order to reduce the pests or kill the weeds or effectively supply nutrients for plants development.
The water used in agriculture is mainly sourced from borewell, open well, dam or river or water streams. The ground water used for agriculture purpose such as spraying various pesticide, weedicide, herbicide, insecticide, pesticide and fungicide is generally hard water having pH >7 because of the hardness causing bicarbonate, carbonate salts of calcium, magnesium and sodium present in the ground water.
It is well known that if one washes the clothes in such hard water clothes are not washed properly and quantity of soap required is more. This is due to the fact that in hard water efficiency of soap is affected and reduced. Due to hardness causing salts, some quantity of soap is hydrolyzed which reduces the efficacy of the washing soap.
Similarly, quality of water used in spray tanks can also affect the efficacy of herbicide or pesticide. Water is the primary carrier for herbicide applications. In fact, it usually makes up over 99% of the spray solution. The chemistry of water added to the spray tank greatly impacts herbicide effectiveness. In the same manner efficiency of applied agrochemicals is also reduced, if one uses the hard water for application of agrochemicals in plants.
Hard water contains high levels of Calcium (Ca), Magnesium (Mg), Sodium (Na) or Iron (Fe). Ca, Mg, Na, and Fe cations are positively charged ions attach to negatively charged pesticide, herbicide, insecticide molecules and due to this reaction often cations make pesticides, herbicides, fungicide, Plant Growth Regulator (PGR) less effective or ineffective.
High pH and hard water act together to reduce effectiveness of agrochemical, pesticide and herbicide. High pH causes more of the pesticide, agrochemical to dissociate while high concentrations of cations bind with the dissociated pesticide, agrochemical to reduce its effectiveness.
If the concentration of all the cations Ca, Mg, Na, and Fe in water exceeds 500 ppm then the water used for pesticide mixing will render the pesticide/agrochemical less effective and the treatment of water is necessary in order to achieve better performance of the herbicide/pesticide/agrochemical or applied agrochemical.
Similarly, if the alkalinity [Alkalinity refers to carbonate ((CO3)2—) and bicarbonate (HCO3—) levels in water] of water exceeds beyond certain value, it contains high bicarbonates and applying pesticide or herbicide in such water will render the herbicide less effective and the treatment of water is necessary in order to achieve better performance of the herbicide or applied agrochemical.
Further, due to the seasonal changes, vicinity of mineral deposits, the hardness and the alkalinity of the ground water changes. Research shows that the “half life” of the chemical varies with pH. Half Life means the time it takes for 50% of the product breakdown (hydrolyze) in water. Each half life that passes reduces the concentration of that agrochemical by 50% i.e. 100%, 50%, 25%, 12.5%, 6.25% and the like. For e.g. products like cypermethrin, glyfosate, benomyl, GA hydrolyze fast in alkaline hard water. Thus, the hard and alkaline water reduces the efficiency of pesticide, insecticide, herbicide, fungicide, PGR, micronutrients, fertilizers and other agrochemicals.
Agricultural chemicals such as pesticides, herbicides, fungicides, PGR, fertilizers, micronutrients are typically applied on plants and soil as an aqueous solution. Many of these agrochemicals have an activity that varies with pH of the solution. Many of these products are sensitive to alkaline waters or acidic waters. Many agrochemicals have optimum activity in slightly acidic pH range of about 4-6, whereas, herbicide like glyfosate functions well at pH=3.5.
Therefore, it is necessary to adjust the pH of the water before the addition of agrochemical into the water to prepare the solution for spraying. The pH correction can be done by acids or alkali and the pH meter or pH paper is required to check the adjustment in the pH made of water using pH modifiers.
Generally, it is time consuming and requires sophisticated delicate pH meter which needs protection from shocks and contact of electronic parts with water. Sensitive pH paper may degrade and be unuseful if it comes in contact with water, high humidity or atmospheric moisture during rainy season. Sometimes determination of pH may show some error because the pH meter needs to be calibrated frequently with different range pH solutions, so it becomes quiet cumbersome in the field to check the pH of the water using above methods. It is required to avoid such problems in the field during the preparation of the solution of pesticide, insecticide, herbicide, fungicide, PGR, micronutrients, fertilizers and other agrochemicals.
U.S. Pat. No. 5,278,132 claims the concentrate which is a mixture of pH modifying agent and a PH indicator which are selected so that the concentrate when diluted in water it adjusts the pH of the water and indicates the pH of water. The pH modifying agents used as acetic acid, orthophosphoric acid, citric acid along with buffers such as ammonia, MAP, MPP, Potassium hydrogen phthalate, sodium acetate. The pH indicator used is member selected from methyl red, recorcin blue, 2-5 di-nitrophenol and chlorophenol red.
PCT Publication No. 2008/035237 discloses a concentrate which includes an adjuvant, a first pH indicator, and a second pH indicator. The pH lower limit of the first pH indicator corresponds to the pH upper limit of the second indicator. Preferably, at this pH, the color of the indicators is the same, and is preferably a light color (e.g. yellow).
PCT Publication No. 2005/018334 discloses the pH indicator for use with Agricultural Compounds. Said publication discloses new class of pH indicators which are mainly naturally occurring substances from grape skin, cabbage and lecithin as adjuvant emulsifier. This publication uses orthophosphoric esters as pH modifying agents.
US Publication No. 2010/0120619 describes the concentration for dilution with water in the preparation of agricultural compositions and its application on crops and animals. The concentrate indicates different colors of spray water at different pH levels. The color changes is as Blue at to yellow at pH about 5.0-5.5 indicated by bromocresol green indicator and color change of yellow to orange red at 3.0-3.5 as indicated by methyl yellow.
Two groups of pH indicators are used in U.S. '619, one group of pH indicator is selected such that intermediate color that is overlapping color of lower end of one pH indicator and the higher end of the other group of pH indicator is same.
The pH indicators discussed are—
For color change of Green to Yellow to orange/red are:—
Group 1:—bromocresol green (Blue at pH 7.4 and yellow at pH 5.6),
                bromoxylenol blue (blue at pH 5.6 and yellow at pH 4.0),Group 2:—Methyl yellow (yellow at pH 4.5 and red at pH 3.2),        methyl orange (yellow at pH 4.5 and red at pH 3.2),        Naphtyl Red (yellow at pH 5.0 and red at pH 3.7).        
For color change of purple to yellow to orange/red:—
Group 3:—Bromophenol red (purple at pH 7.0 and yellow at pH 5.2),
                chlorophenol red (purple-red at pH 6.6 and yellow at pH 5.2),        alizarin red (red at pH 6 and yellow at pH 4.4),        cochineal (purple at pH 6.2 and yellow at pH 4.8),Group 4:—Methyl yellow (yellow at pH 4.5 and red at pH 3.2),        methyl orange (yellow at pH 4.5 and red at pH 3.2),        Naphtyl Red (yellow at pH 5.0 and red at pH 3.7).        
For acidic sensitive agrochemicals fungicides alkaline pH indicators from following group are used.
Group 5:—Xylenol blue (blue at pH 9.5 and yellow at pH 8.0)
                O-cresol red (red at pH 8.8 and yellow at pH 7.2)        M cresol purple (purple at pH 9.2 and yellow at pH 7.6)        1-Naptholbenzene (green at pH 9.8 and yellow at pH 8.4).Group 6:—Neutral red (yellow at pH 8.0 and red at pH 6.8)        
Further, U.S. '619 uses orthophosphric acid, acetic acid, nitric acid, hydrochloric acid, sulfuric acid and formic acid as pH modifying agents. The concentrate disclosed gives benefit to have pH indication at 2 different pH levels by showing 2 different colors. The color change at pH 5.5 i.e. lower end is yellow using various pH indicators. Sometime in the field, when the water is not clear or become dirty due to dirt in rainy season then the color of the water become turbid and it becomes difficult to recognize of yellow color imparted to water by pH indicator.
US Patent Publication No. 2012/0157317 discloses a concentrate in which the pH indicator is triarylmethane and the adjuvant is a carbohydrate (organic) acid for pH modification. The invention provides composition in concentrated form for dilution with water in the preparation of agricultural composition for application to crops, soil or animals. The pH modifying agent used is carbohydrate acid selected from glucoheptonic acid, gluconic acid, glucuronic acid, glucaric acid, mannonic acid, mannuronic acid, mannaric acid, galactonic acid, galactaric acid, galacturonic acid, guluronic acid, iduronic acid, ribonic acid, arabonic acid, xylonic acid, eruythronic acid, threonic acid, tartaric acid and any composition thereof. It also mentioned about the other acids such as acetic acid, orthophisphoric acid, citric acid, glutaric acid, glycolic acid, lactic acid, malonic acid, oxalic acid, phthalic acid, succinic acid, phosphorous acid, amino-tris(methylenephosphonic) acids and etidronic acid. The said patent uses carbohydrate acid for pH modification.
PCT Publication No. WO9925189 claims a concentrate for enhancing the activity of an agricultural chemical comprising pH modifying agents and water conditioning agents; along with a pH indicator for coloring water; the pH indicator producing a colour change in water at a pH at which the agricultural chemical has an acceptable agricultural activity. The pH modifying agent is selected from the group comprising acids, alkalis, buffers and salts for controlling or modifying the pH of water and the pH indicator is selected from the group comprising methyl red, bromocresol purple, and bromocresol green.
Abstract of Chinese Patent Publication No. CN1372796 describes a concentrated chemical for agricultural purpose, such as for crops, soil or animals, can be diluted by water, and contains the chemical and pH value indicator able to dye water. It characterized by that the activity of said chemical changes with the pH value of water, so visually indicating the activity of said chemical according to the color of liquid.
Though, the above mentioned prior art patents/patent Publications teaches the use of pH modifying agent with pH indicator, however, the agriculture composition mentioned above does not offer any other benefits than pH adjustment and pH indication using pH indicators.
Therefore, there is a need in the art to provide a more effective composition in the field of agriculture, hence, the inventor of the present invention have come up with a multifunctional adjuvant chemical composition, which offers multiple benefits by acting in multiple ways and reduce the usage of agrochemicals by effectively increasing their efficiency about 25-35% by treating the water for its hardness causing salts which render the agrochemicals/pesticides less effective.
The multifunctional adjuvant chemical composition for use in agriculture to treat the water for its hardness by using pH correctors automatically allow the end user to know the pH of the corrected water by visual indication instead of taking the use of large cumbersome, difficult to handle pH meters and pH papers. The multifunctional chemical composition also has surface tension reducing property and thus enhances the coverage of applied agrochemical.
The additional features of the present composition is that, apart from treating the water for its hardness causing salts, it also acts to improve the immune system and defense mechanism of plant and supplies nutrient such as phosphite ion, nitrogen in the form amino acids, hard water containing calcium and magnesium in the form of complexed phosphite salts and hormone in the form of pH indicator.